# Chapter 4 - Molecular energy levels¶

## Example 1 - pg 104¶

In [1]:
#calculate the Moment of inertia
#initialization of variables
import math
B=10.34 #cm**-1
c=2.998*10**10 #cm/s
h=6.625*10**-27 #erg sec
#calculations
I=h/(8*math.pi**2 *B*c)
#results
print '%s %.2e %s' %("Moment of inertia =",I," g cm^2")

Moment of inertia = 2.71e-40  g cm^2


## Example 2 - pg 105¶

In [2]:
#calculate the Bond length
#Initialization of variables
import math
ma=1.0080
mb=35.457
Na=6.0232*10**23
I=2.707*10**-40 #g cm**2
#calculations
mu1=ma*mb/(ma+mb)
mu2=mu1/Na
r=math.sqrt(I/mu2)
#results
print '%s %.2e %s' %("Bond length =",r,"cm")

Bond length = 1.29e-08 cm


# Example 3 - pg 110¶

In [3]:
#calculate the Force constant
#Initialization of variables
import math
c=2.998*10**10 #cm/s
wave=2990 #cm**-1
mu=1.627*10**-24 #g
#calculations
k=mu*(2*math.pi*c*wave)**2
#results
print '%s %.2e %s' %("Force constant =",k,"dynes/cm")

Force constant = 5.16e+05 dynes/cm


## Example 4 - pg 111¶

In [4]:
#calculate the anharmonicity constant
#initialization of variables
l1=2886. #cm^-1
l2=5668. #cm^-1
#calculations
wave=2*l1-l2
wave2= wave+l1
x=wave/(2*wave2)
#results
print '%s %.4f' %("anharmonicity constant = ",x)

anharmonicity constant =  0.0174